Exposure to Prenatal Social Disadvantage and Maternal Psychosocial Stress: Relationships to Neonatal White Matter Connectivity

Abstract

ABSTRACTChildhood exposure to poverty and related psychosocial stressors are associated with altered microstructure in fronto-limbic pathways evident at age 8-10 years. How early in neurodevelopment these associations can be detected remains unclear. In this longitudinal study, 399 mothers were oversampled for low income and completed social experience and background measures during pregnancy. Measures were analyzed with structural equation analysis resulting in two latent constructs: Social Disadvantage (education, insurance status, income-to-needs ratio [INR], neighborhood deprivation, nutrition) and Psychosocial Stress (depression, stress, life events, racial discrimination). At birth, 289 healthy term-born neonates underwent a diffusion MRI (dMRI) scan. Mean diffusivity (MD) and fractional anisotropy (FA) were measured for the dorsal and inferior cingulum bundle (CB), uncinate, and fornix using probabilistic tractography in FSL. Social Disadvantage and Psychosocial Stress were fitted to dMRI parameters using regression models adjusted for infant postmenstrual age at scan and sex. Social Disadvantage, but not Psychosocial Stress, was independently associated with lower MD in the bilateral inferior CB and left uncinate, right fornix, and lower MD and higher FA in the right dorsal CB. Results persisted after accounting for maternal medical risk in pregnancy and prenatal drug exposure. In moderation analysis, Psychosocial Stress was associated with lower MD in the left inferior CB among the lower-to-higher SES (INR ≥200%) group, but not the extremely low SES (INR <200%) group. Increasing access to social welfare programs that reduce the burden of poverty and related psychosocial stressors may be an important target to protect fetal brain development in fronto-limbic pathways.